This page has only limited features, please log in for full access.
This study aimed to present a new ictal component selection technique, named as recursive ICA-decomposition for ictal component selection (RIDICS), for potential application in epileptogenic zone localization. The proposed technique decomposes ictal EEG recursively, eliminates a few unwanted components in every recursive cycle, and finally selects the most significant ictal component. Back-projected EEG, regenerated from that component, was used for source estimation. Fifty sets of simulated EEGs and 24 seizures in 8 patients were analyzed. Dipole sources of simulated-EEGs were compared with a known dipole location whereas epileptogenic zones of the seizures were compared with their corresponding sites of successful surgery. The RIDICS technique was compared with a conventional technique. The RIDICS technique estimated the dipole sources at an average distance of 12.86 mm from the original dipole location, shorter than the distances obtained using the conventional technique. Epileptogenic zones of the patients, determined by the RIDICS technique, were highly concordant with the sites of surgery with a concordance rate of 83.33%. Results show that the RIDICS technique can be a promising quantitative technique for ictal component selection. Properly selected ictal component gives good approximation of epileptogenic zone, which eventually leads to successful epilepsy surgery.
Mohammad Ashfak Habib; Fatimah Ibrahim; Mas S. Mohktar; Shahrul Bahyah Kamaruzzaman; Kheng Seang Lim. Recursive independent component analysis (ICA)-decomposition of ictal EEG to select the best ictal component for EEG source imaging. Clinical Neurophysiology 2019, 131, 642 -654.
AMA StyleMohammad Ashfak Habib, Fatimah Ibrahim, Mas S. Mohktar, Shahrul Bahyah Kamaruzzaman, Kheng Seang Lim. Recursive independent component analysis (ICA)-decomposition of ictal EEG to select the best ictal component for EEG source imaging. Clinical Neurophysiology. 2019; 131 (3):642-654.
Chicago/Turabian StyleMohammad Ashfak Habib; Fatimah Ibrahim; Mas S. Mohktar; Shahrul Bahyah Kamaruzzaman; Kheng Seang Lim. 2019. "Recursive independent component analysis (ICA)-decomposition of ictal EEG to select the best ictal component for EEG source imaging." Clinical Neurophysiology 131, no. 3: 642-654.
We developed and modeled tunable reversible valves on microfluidic discs, and employed them to automate a multiplexed immunoassay with peptide microarrays.
Mohammad Mahdi Aeinehvand; Laura Weber; Martín Jiménez; Andrea Palermo; Maria Bauer; Felix F. Loeffler; Fatimah Ibrahim; Frank Breitling; Jan Korvink; Marc Madou; Dario Mager; Sergio O. Martínez-Chapa. Elastic reversible valves on centrifugal microfluidic platforms. Lab on a Chip 2019, 19, 1090 -1100.
AMA StyleMohammad Mahdi Aeinehvand, Laura Weber, Martín Jiménez, Andrea Palermo, Maria Bauer, Felix F. Loeffler, Fatimah Ibrahim, Frank Breitling, Jan Korvink, Marc Madou, Dario Mager, Sergio O. Martínez-Chapa. Elastic reversible valves on centrifugal microfluidic platforms. Lab on a Chip. 2019; 19 (6):1090-1100.
Chicago/Turabian StyleMohammad Mahdi Aeinehvand; Laura Weber; Martín Jiménez; Andrea Palermo; Maria Bauer; Felix F. Loeffler; Fatimah Ibrahim; Frank Breitling; Jan Korvink; Marc Madou; Dario Mager; Sergio O. Martínez-Chapa. 2019. "Elastic reversible valves on centrifugal microfluidic platforms." Lab on a Chip 19, no. 6: 1090-1100.
The development of easy to use, rapid and sensitive methods for direct detection of foodborne bacterial pathogens has become significantly important due to their impact on human health. In recent years, carbon nanomaterials have been adapted in the fabrication of electrochemical biosensors due to their exceptional combination of intrinsic properties such as high conductivity, stability and biocompatibility that render them as a promising candidate for bio-sensing material. The scope of this review is to provide a brief history of the current methods and different types of electrochemical biosensors used for the detection of bacterial pathogens. We primarily focus on the recent progress and applications of graphene, carbon nanotubes and their derivatives in electrochemical biosensors for foodborne bacterial pathogens detection. Finally, the status and future prospects of carbon-based electrochemical biosensors are also reviewed and discussed.
Shalini Muniandy; Swe Jyan Teh; Kwai Lin Thong; Aung Thiha; Ignatius Julian Dinshaw; Chin Wei Lai; Fatimah Ibrahim; Bey Fen Leo. Carbon Nanomaterial-Based Electrochemical Biosensors for Foodborne Bacterial Detection. Critical Reviews in Analytical Chemistry 2019, 49, 510 -533.
AMA StyleShalini Muniandy, Swe Jyan Teh, Kwai Lin Thong, Aung Thiha, Ignatius Julian Dinshaw, Chin Wei Lai, Fatimah Ibrahim, Bey Fen Leo. Carbon Nanomaterial-Based Electrochemical Biosensors for Foodborne Bacterial Detection. Critical Reviews in Analytical Chemistry. 2019; 49 (6):510-533.
Chicago/Turabian StyleShalini Muniandy; Swe Jyan Teh; Kwai Lin Thong; Aung Thiha; Ignatius Julian Dinshaw; Chin Wei Lai; Fatimah Ibrahim; Bey Fen Leo. 2019. "Carbon Nanomaterial-Based Electrochemical Biosensors for Foodborne Bacterial Detection." Critical Reviews in Analytical Chemistry 49, no. 6: 510-533.
Salmonellosis caused by the bacteria in the genus Salmonella remains the most important foodborne disease in both developing and developed countries. Since several decades various microbial detection and quantification methods have been developed. One of recently developed gene amplification method is loop-mediated isothermal amplification (LAMP) which has been developed on tube-based platform. To facilitate the detection of pathogenic diseases in remote areas, a microfluidic platform has been developed called lab-on-a-CD. This paper presents an improved endpoint detection system for LAMP on Lab-on-a-CD platform. A set of ultraviolet (UV) emitter and color sensor have been used in this detection system to detect the emission level of LAMP amplicons. A LAMP assay has been performed with Salmonella bacteria DNA and calibrated the duty cycle of UV emitter to optimize the amplicons detection system.
Shah Mukim Uddin; Fatimah Ibrahim; Jongman Cho; Kwai Lin Thong. Optimization of the Amplicons Detection System of Loop-Mediated Isothermal Amplification on Microfluidic Compact Disk. VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014 2018, 7 -12.
AMA StyleShah Mukim Uddin, Fatimah Ibrahim, Jongman Cho, Kwai Lin Thong. Optimization of the Amplicons Detection System of Loop-Mediated Isothermal Amplification on Microfluidic Compact Disk. VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014. 2018; ():7-12.
Chicago/Turabian StyleShah Mukim Uddin; Fatimah Ibrahim; Jongman Cho; Kwai Lin Thong. 2018. "Optimization of the Amplicons Detection System of Loop-Mediated Isothermal Amplification on Microfluidic Compact Disk." VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014 , no. : 7-12.
This paper presents the design and numerical analysis of a new three-dimensional (3D) electrode having a non-uniform electric field gradient for dielectrophoretic patterning of liver cells. The strength of the dielectrophoresis (DEP) force is influenced by the gradient of electric field generated by the electrode. The new design of the 3D electrode with two different electrode configurations were first modelled and simulated using COMSOL Multiphysics. Results show that the electrical field distribution of vertical configuration concentrated only on the end strips and decays progressively towards the centre while the horizontal configuration shows a more uniform electric field distribution with minimal decrease of the electric field towards the centre. Besides, the horizontal configuration offered 2.7 times higher of the electrical field strength to establish the 3D DEP force hence the 3D cellular pattern. Thus, the electrode with the horizontal configuration has been proposed and optimized to be fabricated for the cell patterning application later on. The optimum electrode dimension identified in this work was 20 µm: 50 µm (gap: height) with a 20 µm electrode width that generates a maximum value of 1.06 × 106 V/m with a voltage set at 5 V. Increasing voltage leads to a stronger electric field and more DEP force would be imposed on the cells. This findings support that the unique design of the 3D electrode can further be used for dielectrophoretic-based patterning mechanism specifically for the complex liver tissue engineering.
Wan Nurlina Wan Yahya; Nahrizul Adib Kadri; Fatimah Ibrahim. Design and numerical analysis of interdigitated radiating-strips electrode for uniform 3D dielectrophoretic patterning of liver cells. Microsystem Technologies 2018, 25, 3037 -3045.
AMA StyleWan Nurlina Wan Yahya, Nahrizul Adib Kadri, Fatimah Ibrahim. Design and numerical analysis of interdigitated radiating-strips electrode for uniform 3D dielectrophoretic patterning of liver cells. Microsystem Technologies. 2018; 25 (8):3037-3045.
Chicago/Turabian StyleWan Nurlina Wan Yahya; Nahrizul Adib Kadri; Fatimah Ibrahim. 2018. "Design and numerical analysis of interdigitated radiating-strips electrode for uniform 3D dielectrophoretic patterning of liver cells." Microsystem Technologies 25, no. 8: 3037-3045.
Methadone as the most prevalent opioid substitution medication has been shown to influence the neurophysiological functions among heroin addicts. However, there is no firm conclusion on acute neuroelectrophysiological changes among methadone-treated subjects as well as the effectiveness of methadone in restoring brain electrical abnormalities among heroin addicts. This study aims to investigate the acute and short-term effects of methadone administration on the brain’s electrophysiological properties before and after daily methadone intake over 10 weeks of treatment among heroin addicts. EEG spectral analysis and single-trial event-related potential (ERP) measurements were used to investigate possible alterations in the brain’s electrical activities, as well as the cognitive attributes associated with MMN and P3. The results confirmed abnormal brain activities predominantly in the beta band and diminished information processing ability including lower amplitude and prolonged latency of cognitive responses among heroin addicts compared to healthy controls. In addition, the alteration of EEG activities in the frontal and central regions was found to be associated with the withdrawal symptoms of drug users. Certain brain regions were found to be influenced significantly by methadone intake; acute effects of methadone induction appeared to be associative to its dosage. The findings suggest that methadone administration affects cognitive performance and activates the cortical neuronal networks, resulting in cognitive responses enhancement which may be influential in reorganizing cognitive dysfunctions among heroin addicts. This study also supports the notion that the brain’s oscillation powers and ERPs can be utilized as neurophysiological indices for assessing the addiction treatment traits.
Farid Motlagh; Fatimah Ibrahim; Rusdi Rashid; Niusha Shafiabady; Tahereh Seghatoleslam; Hussain Habil. Acute effects of methadone on EEG power spectrum and event-related potentials among heroin dependents. Psychopharmacology 2018, 235, 3273 -3288.
AMA StyleFarid Motlagh, Fatimah Ibrahim, Rusdi Rashid, Niusha Shafiabady, Tahereh Seghatoleslam, Hussain Habil. Acute effects of methadone on EEG power spectrum and event-related potentials among heroin dependents. Psychopharmacology. 2018; 235 (11):3273-3288.
Chicago/Turabian StyleFarid Motlagh; Fatimah Ibrahim; Rusdi Rashid; Niusha Shafiabady; Tahereh Seghatoleslam; Hussain Habil. 2018. "Acute effects of methadone on EEG power spectrum and event-related potentials among heroin dependents." Psychopharmacology 235, no. 11: 3273-3288.
This study investigates a new approach to determine the correlations between alpha ([Formula: see text]) electroencephalography (EEG) and other physiological parameters during Muslim prayer (Salat) utilizing the self organizing map (SOM). The powerfulness of SOM in visualizing, understanding, and exploring the complexity in multivariable data can be used to determine the relationships between the input variables. Thirty healthy Muslim male subjects were recruited in the study. Their electroencephalogram (EEG), electrocardiogram (ECG), respiration rate (RSP), and oxygen saturation (SPO2) were continuously recorded using computer-based data acquisition system (MP150, BIOPAC Systems Inc., Camino Goleta, California). Three maps were constructed to determine the correlations in pre-baseline, during Salat, and post-baseline conditions utilizing SOM. The visualized results during Salat indicated that, alpha power (P[Formula: see text]) showed significant positive correlation in the occipital and parietal electrodes with the normalized unit of high-frequency HF (n.u.) power of heart rate variability (HRV) components (as a parasympathetic index), heart rate (HR), and RSP. Significant negative correlation was also observed between P[Formula: see text] with the normalized unit of low-frequency LF (n.u.) power and LF/HF of HRV (as sympathetic indices). SPO2 showed no correlation with P[Formula: see text]. While the results in pre-baseline and post-baseline conditions also did not show any correlation between the variables. The SOM proves that it can be successfully employed as a powerful technique in correlation analysis. The results were presented and compared with a previous study. Thus, it can be applied successfully in various biomedical engineering applications.
Hazem Doufesh; Fatimah Ibrahim; Noor Azina Ismail; Wan Azman Wan Ahmad. APPLICATION OF SELF ORGANIZING MAP FOR CORRELATION HUNTING BETWEEN ALPHA BAND POWER OF EEG SIGNALS AND OTHER PHYSIOLOGICAL PARAMETERS DURING MUSLIM PRAYER (SALAT). Biomedical Engineering: Applications, Basis and Communications 2018, 30, 1 .
AMA StyleHazem Doufesh, Fatimah Ibrahim, Noor Azina Ismail, Wan Azman Wan Ahmad. APPLICATION OF SELF ORGANIZING MAP FOR CORRELATION HUNTING BETWEEN ALPHA BAND POWER OF EEG SIGNALS AND OTHER PHYSIOLOGICAL PARAMETERS DURING MUSLIM PRAYER (SALAT). Biomedical Engineering: Applications, Basis and Communications. 2018; 30 (4):1.
Chicago/Turabian StyleHazem Doufesh; Fatimah Ibrahim; Noor Azina Ismail; Wan Azman Wan Ahmad. 2018. "APPLICATION OF SELF ORGANIZING MAP FOR CORRELATION HUNTING BETWEEN ALPHA BAND POWER OF EEG SIGNALS AND OTHER PHYSIOLOGICAL PARAMETERS DURING MUSLIM PRAYER (SALAT)." Biomedical Engineering: Applications, Basis and Communications 30, no. 4: 1.
In this study, an amino-modified aptasensor using multi-walled carbon nanotubes (MWCNTs)-deposited ITO electrode was prepared and evaluated for the detection of pathogenic Salmonella bacteria. An amino-modified aptamer (ssDNA) which binds selectively to whole-cell Salmonella was immobilised on the COOH-rich MWCNTs to produce the ssDNA/MWCNT/ITO electrode. The morphology of the MWCNT before and after interaction with the aptamers were observed using scanning electron microscopy (SEM). Cyclic voltammetry and electrochemical impedance spectroscopy techniques were used to investigate the electrochemical properties and conductivity of the aptasensor. The results showed that the impedance measured at the ssDNA/MWCNT/ITO electrode surface increased after exposure to Salmonella cells, which indicated successful binding of Salmonella on the aptamer-functionalised surface. The developed ssDNA/MWCNT/ITO aptasensor was stable and maintained linearity when the scan rate was increased from 10 mV s−1 to 90 mV s−1. The detection limit of the ssDNA/MWCNT/ITO aptasensor, determined from the sensitivity analysis, was found to be 5.5 × 101 cfu mL−1 and 6.7 × 101 cfu mL−1 for S. Enteritidis and S. Typhimurium, respectively. The specificity test demonstrated that Salmonella bound specifically to the ssDNA/MWCNT/ITO aptasensor surface, when compared with non-Salmonella spp. The prepared aptasensor was successfully applied for the detection of Salmonella in food samples.
Rakibul Hasan; Thiruchelvi Pulingam; Jimmy Nelson Appaturi; Anis Nadyra Zifruddin; Swe Jyan Teh; Teck Wei Lim; Fatimah Ibrahim; Bey Fen Leo; Kwai Lin Thong. Carbon nanotube-based aptasensor for sensitive electrochemical detection of whole-cell Salmonella. Analytical Biochemistry 2018, 554, 34 -43.
AMA StyleRakibul Hasan, Thiruchelvi Pulingam, Jimmy Nelson Appaturi, Anis Nadyra Zifruddin, Swe Jyan Teh, Teck Wei Lim, Fatimah Ibrahim, Bey Fen Leo, Kwai Lin Thong. Carbon nanotube-based aptasensor for sensitive electrochemical detection of whole-cell Salmonella. Analytical Biochemistry. 2018; 554 ():34-43.
Chicago/Turabian StyleRakibul Hasan; Thiruchelvi Pulingam; Jimmy Nelson Appaturi; Anis Nadyra Zifruddin; Swe Jyan Teh; Teck Wei Lim; Fatimah Ibrahim; Bey Fen Leo; Kwai Lin Thong. 2018. "Carbon nanotube-based aptasensor for sensitive electrochemical detection of whole-cell Salmonella." Analytical Biochemistry 554, no. : 34-43.
Nanowire sensors offer great potential as highly sensitive electrochemical and electronic biosensors because of their small size, high aspect ratios, and electronic properties. Nevertheless, the available methods to fabricate carbon nanowires in a controlled manner remain limited to expensive techniques. This paper presents a simple fabrication technique for sub-100nm suspended carbon nanowire sensors by integrating electrospinning and photolithography techniques. Carbon Microelectromechanical Systems (C-MEMS) fabrication techniques allow fabrication of high aspect ratio carbon structures by patterning photoresist polymers into desired shapes and subsequent carbonization of resultant structures by pyrolysis. In our sensor platform, suspended nanowires were deposited by electrospinning while photolithography was used to fabricate support structures. We have achieved suspended carbon nanowires with sub-100 nm diameters in this study. The sensor platform was then integrated with a microfluidic chip to form a lab-on-chip device for label-free chemiresistive biosensing. We have investigated this nanoelectronics label-free biosensor's performance towards bacterial sensing by functionalization with Salmonella-specific aptamer probes. The device was tested with varying concentrations of Salmonella Typhimurium to evaluate sensitivity and various other bacteria to investigate specificity. The results showed that the sensor is highly specific and sensitive in detection of Salmonella with a detection limit of 10 CFU mL−1. Moreover, this proposed chemiresistive assay has a reduced turnaround time of 5 minutes and sample volume requirement of 5 µL which are much less than reported in the literature.
Aung Thiha; Fatimah Ibrahim; Shalini Muniandy; Ignatius Julian Dinshaw; Swe Jyan Teh; Kwai Lin Thong; Bey Fen Leo; Marc Madou. All-carbon suspended nanowire sensors as a rapid highly-sensitive label-free chemiresistive biosensing platform. Biosensors and Bioelectronics 2018, 107, 145 -152.
AMA StyleAung Thiha, Fatimah Ibrahim, Shalini Muniandy, Ignatius Julian Dinshaw, Swe Jyan Teh, Kwai Lin Thong, Bey Fen Leo, Marc Madou. All-carbon suspended nanowire sensors as a rapid highly-sensitive label-free chemiresistive biosensing platform. Biosensors and Bioelectronics. 2018; 107 ():145-152.
Chicago/Turabian StyleAung Thiha; Fatimah Ibrahim; Shalini Muniandy; Ignatius Julian Dinshaw; Swe Jyan Teh; Kwai Lin Thong; Bey Fen Leo; Marc Madou. 2018. "All-carbon suspended nanowire sensors as a rapid highly-sensitive label-free chemiresistive biosensing platform." Biosensors and Bioelectronics 107, no. : 145-152.
Antioxidants are an important substance that can fight the deterioration of free radicals and can easily oxidize when exposed to light. There are many methods to measure the antioxidant activity in a biological sample, for example 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity test, which is one of the simplest methods used. Despite its simplicity, the organic solvent that has been used to dilute DPPH is easily evaporated and degraded with respect to light exposure and time. Thus, it needs to be used at the earliest convenient time prior to the experiment. To overcome this issue, a rapid and close system for antioxidant activity is required. In this paper, we introduced the Lab-on-a-Disc (LoD) method that integrates the DPPH antioxidant activity test on a microfluidic compact disc (CD). We used ascorbic acid, quercetin, Areca catechu, Polygonum minus, and Syzygium polyanthum plant extracts to compare the results of our proposed LoD method with the conventional method. Contrasted to the arduous laborious conventional method, our proposed method offer rapid analysis and simple determination of antioxidant. This proposed LoD method for antioxidant activity in plants would be a platform for the further development of antioxidant assay.
Nurhaslina Abd Rahman; Fatimah Ibrahim; Mohammad M. Aeinehvand; Rohana Yusof; Marc Madou. A Microfluidic Lab-on-a-Disc (LOD) for Antioxidant Activities of Plant Extracts. Micromachines 2018, 9, 140 .
AMA StyleNurhaslina Abd Rahman, Fatimah Ibrahim, Mohammad M. Aeinehvand, Rohana Yusof, Marc Madou. A Microfluidic Lab-on-a-Disc (LOD) for Antioxidant Activities of Plant Extracts. Micromachines. 2018; 9 (4):140.
Chicago/Turabian StyleNurhaslina Abd Rahman; Fatimah Ibrahim; Mohammad M. Aeinehvand; Rohana Yusof; Marc Madou. 2018. "A Microfluidic Lab-on-a-Disc (LOD) for Antioxidant Activities of Plant Extracts." Micromachines 9, no. 4: 140.
Background: Skin is the largest and most visible organ of the body. Many of its functions include temperature regulation, immunity from microorganisms, maintaining electrolyte balance, and protection from physical injuries, chemical agents and ultraviolet (UV) radiation. Aging occurs in every layer of the skin, primarily due to the degradation of its components. Induction of degradative enzymes and the abundant production of reactive oxygen species lead to skin aging. Understanding the complexity of skin structure and factors contributing to the skin aging will help us impede the aging process. Applications of anti-aging products are a common method to prevent or repair damages that lead to aging. Conclusion: This review will provide information on the causes and indicators of skin aging as well as examine studies that have used plants to produce anti-aging products.
Zaliyatun A.M. Yasin; Fatimah Ibrahim; Nurshamimi N. Rashid; Muhammad F.M. Razif; Rohana Yusof; Fatimah Ibrahim Zaliyatun Akhma Mat Yasin. The Importance of Some Plant Extracts as Skin Anti-aging Resources: A Review. Current Pharmaceutical Biotechnology 2018, 18, 864 -876.
AMA StyleZaliyatun A.M. Yasin, Fatimah Ibrahim, Nurshamimi N. Rashid, Muhammad F.M. Razif, Rohana Yusof, Fatimah Ibrahim Zaliyatun Akhma Mat Yasin. The Importance of Some Plant Extracts as Skin Anti-aging Resources: A Review. Current Pharmaceutical Biotechnology. 2018; 18 (11):864-876.
Chicago/Turabian StyleZaliyatun A.M. Yasin; Fatimah Ibrahim; Nurshamimi N. Rashid; Muhammad F.M. Razif; Rohana Yusof; Fatimah Ibrahim Zaliyatun Akhma Mat Yasin. 2018. "The Importance of Some Plant Extracts as Skin Anti-aging Resources: A Review." Current Pharmaceutical Biotechnology 18, no. 11: 864-876.
Outbreaks of foodborne diseases have become a global health concern; hence, many improvements and developments have been made to reduce the risk of food contamination. We developed a centrifugal microfluidic automatic wireless endpoint detection system integrated with loop mediated isothermal amplification (LAMP) for monoplex pathogen detection. Six identical sets were designed on the microfluidic compact disc (CD) to perform 30 genetic analyses of three different species of foodborne pathogens. The consecutive loading, mixing, and aliquoting of the LAMP primers/reagents and DNA sample solutions were accomplished using an optimized square-wave microchannel, metering chambers and revulsion per minute (RPM) control. We tested 24 strains of pathogenic bacteria (Escherichia coli, Salmonella spp and Vibrio cholerae), with 8 strains of each bacterium, and performed DNA amplification on the microfluidic CD for 60min. Then, the amplicons of the LAMP reaction were detected using the calcein colorimetric method and further analysed via the developed electronic system interfaced with Bluetooth wireless technology to transmit the results to a smartphone. The system showed a limit of detection (LOD) of 3 × 10(-5)ngμL(-1) DNA by analysing the colour change when tested with chicken meat spiked with the three pathogenic bacteria. Since the entire process was performed in a fully automated way and was easy to use, our microdevice is suitable for point-of-care (POC) testing with high simplicity, providing affordability and accessibility even to poor, resource-limited settings.
Abkar Sayad; Fatimah Ibrahim; Shah Mukim Uddin; Jongman Cho; Marc Madou; Kwai Lin Thong. A microdevice for rapid, monoplex and colorimetric detection of foodborne pathogens using a centrifugal microfluidic platform. Biosensors and Bioelectronics 2018, 100, 96 -104.
AMA StyleAbkar Sayad, Fatimah Ibrahim, Shah Mukim Uddin, Jongman Cho, Marc Madou, Kwai Lin Thong. A microdevice for rapid, monoplex and colorimetric detection of foodborne pathogens using a centrifugal microfluidic platform. Biosensors and Bioelectronics. 2018; 100 ():96-104.
Chicago/Turabian StyleAbkar Sayad; Fatimah Ibrahim; Shah Mukim Uddin; Jongman Cho; Marc Madou; Kwai Lin Thong. 2018. "A microdevice for rapid, monoplex and colorimetric detection of foodborne pathogens using a centrifugal microfluidic platform." Biosensors and Bioelectronics 100, no. : 96-104.
MEMS piezoresistive pressure sensors have been contemporarily used to measure intracranial pressure. Since an intracranial signal is of the pulsating type, the microsensor must be very sensitive to detect these changes. The sensitivity of the existing MEMS piezoresistive intracranial pressure sensors are in the range of 2 µV/V/mmHg to 0.17 mV/V/mmHg. Factors influencing the sensitivity and linearity of the sensor include the diaphragm thickness, the shape and placement of the piezoresistors, and the doping concentration. This paper will discuss the incorporation of these factors, which were tested to obtain higher sensitivity silicon-based piezoresistive intracranial pressure sensor, while maintaining the linearity of the sensor. In order to achieve this objective, the Taguchi robust design method of L27 orthogonal array was employed. The sensing outputs of these designs, with different combinations of factors were determined through simulations using COMSOL Multiphysics. The results indicated that the diaphragm thickness and perpendicular piezoresistors play important roles in the sensitivity performance of the MEMS piezoresistive intracranial pressure sensor. The findings also showed that the doping concentration of the piezoresistors have significant effect on the linearity performance of the sensor. Consequently, the design that consolidated the 3-turns (perpendicular) and 0-turn (parallel) meander shaped piezoresistors of 1017 cm−3 dopant concentration on a 2 μm diaphragm thickness was found to be the optimum design, with sensitivity of 0.1272 mV/V/mmHg and linearity of 99%. This design has been proven to be an improved version for the small diaphragm piezoresistive intracranial pressure sensor.
Mazita Mohamad; Norhayati Soin; Fatimah Ibrahim. Design optimisation of high sensitivity MEMS piezoresistive intracranial pressure sensor using Taguchi approach. Microsystem Technologies 2018, 24, 2637 -2652.
AMA StyleMazita Mohamad, Norhayati Soin, Fatimah Ibrahim. Design optimisation of high sensitivity MEMS piezoresistive intracranial pressure sensor using Taguchi approach. Microsystem Technologies. 2018; 24 (6):2637-2652.
Chicago/Turabian StyleMazita Mohamad; Norhayati Soin; Fatimah Ibrahim. 2018. "Design optimisation of high sensitivity MEMS piezoresistive intracranial pressure sensor using Taguchi approach." Microsystem Technologies 24, no. 6: 2637-2652.
Centrifugal microfluidics is a field that has attracted many researchers over the last two decades and its application to biomedical analysis has been investigated intensively. This review paper presents recently developed innovative micropumps, microvalves and micromixers on microfluidic CDs that enabled the automation and integration of sequential bioanalytical assays. We also introduce and compare recent innovations in sensing and detection approaches in centrifugal microfluidic platforms. In this context, we propose the integration of carbon interdigitated electrode arrays (C-IDEAs) biosensors and microballoon fluidic components for the future development of highly sensitive, inexpensive and low-power consuming point-of-care (POC) diagnostic devices. To enable power on the CDs for the C-IDEAs biosensors, we review different formats for transferring power to the spinning platforms.
Mohammad Mahdi Aeinehvand; Fatimah Ibrahim; Wisam Al Faqheri; Karunan Joseph; Marc J. Madou. Recent advances in the development of micropumps, microvalves and micromixers and the integration of carbon electrodes on centrifugal microfluidic platforms. International Journal of Nanotechnology 2018, 15, 53 .
AMA StyleMohammad Mahdi Aeinehvand, Fatimah Ibrahim, Wisam Al Faqheri, Karunan Joseph, Marc J. Madou. Recent advances in the development of micropumps, microvalves and micromixers and the integration of carbon electrodes on centrifugal microfluidic platforms. International Journal of Nanotechnology. 2018; 15 (1/2/3):53.
Chicago/Turabian StyleMohammad Mahdi Aeinehvand; Fatimah Ibrahim; Wisam Al Faqheri; Karunan Joseph; Marc J. Madou. 2018. "Recent advances in the development of micropumps, microvalves and micromixers and the integration of carbon electrodes on centrifugal microfluidic platforms." International Journal of Nanotechnology 15, no. 1/2/3: 53.
This paper presents the fabrication of low-resistance carbon MEMS/NEMS as material for biosensing. The carbon source is the negative photoresist SU8 epoxy. At room temperature the SU8 is in liquid form, making it easier to mix with nanoparticles. The SU8 epoxy is mixed with single-walled-Carbon-Nanotubes (swCNTs) and stirred for 48 h. The experimental variable was the weight percentage (wt%) of swCNTs in the SU8 epoxy. The controlled variables were the layer thickness and experimental environment such as the room’s humidity and furnace model. The silicon wafer was used as substrate because it can withstand high temperatures during the pyrolysis step. The spin coater was used for coating the mixture onto the substrates uniformly. The spinning process was repeated for sample design 2 and 3 to obtain the double layer characteristic. Samples were exposed to ultra-violet (UV) radiation for 40 s. This process is called photolithography. The samples were heated on the hotplate before (pre-bake) and after (post-bake) the photolithography step for solvent evaporation. SU8 developer solution and acetone were used to remove the un-exposed SU8 for pattern developer. Finally, the samples were carbonized at 900 °C maximum in an oxygen free environment (purified Nitrogen gas (N2) gas 99.9995%). The experimental result showed that the lowest possible resistance value was 25 Ω for the sample design 2 and 3 at 0.01 wt% swCNTs.
M. F. Zulkeflee; F. Ibrahim; M. Madou. Fabrication of Low-Resistance Carbon MEMS/NEMS as Material for Biosensing. VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014 2017, 131 -134.
AMA StyleM. F. Zulkeflee, F. Ibrahim, M. Madou. Fabrication of Low-Resistance Carbon MEMS/NEMS as Material for Biosensing. VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014. 2017; ():131-134.
Chicago/Turabian StyleM. F. Zulkeflee; F. Ibrahim; M. Madou. 2017. "Fabrication of Low-Resistance Carbon MEMS/NEMS as Material for Biosensing." VI Latin American Congress on Biomedical Engineering CLAIB 2014, Paraná, Argentina 29, 30 & 31 October 2014 , no. : 131-134.
Microfluidics compact disc (CD) system has offer many advantages to biological and chemical analysis. It simplifies the procedures and miniaturize the sample and reagent volume. Beads has been used in the microfluidics CD technology in order to enhance the mixing of the reagents or sample. However, the effect of the beads need to be monitor to ensure the effectiveness, biocompatibility and corrosion protection of the beads. This paper has presented the advantage of photoprotective microfluidic CD for Boesenbergia rotunda antioxidant activity and the effect of magnetic bead in enhancing the reaction time of the mixing. The results have shown that, with the magnetic beads usage, the uniformity time of the liquid mixing in the reaction chamber are faster than the non-beads reaction chamber. However, in terms of the stability, the beads have been found to give an interference to the Boesenbergia rotunda 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity. To solve this issues, we would recommend an inert coating of the beads to prevent a chemical reaction between the beads and the free radical’s reagents. The proposed method has minimized human handling in the DPPH plant antioxidant activity by using microfluidics CD with imitation of the real test environment in the conventional method (photoprotective). Consequently, the laborious repetitive routine in the laboratories, which is one of the factor in pre-analytical error has been reduced. This system would be a great advantage to the future laboratories techniques, as it can be applied as a point of care testing and be used in the small laboratories.
Nurhaslina Abd Rahman; Fatimah Ibrahim; M. Mahdi Ainehvand; Rohana Yusof; Marc Madou. An Effect of Magnetic Beads to Boesenbergia rotunda Antioxidant Activity Using Photoprotective Microfluidic CD. 8th European Medical and Biological Engineering Conference 2017, 139 -144.
AMA StyleNurhaslina Abd Rahman, Fatimah Ibrahim, M. Mahdi Ainehvand, Rohana Yusof, Marc Madou. An Effect of Magnetic Beads to Boesenbergia rotunda Antioxidant Activity Using Photoprotective Microfluidic CD. 8th European Medical and Biological Engineering Conference. 2017; ():139-144.
Chicago/Turabian StyleNurhaslina Abd Rahman; Fatimah Ibrahim; M. Mahdi Ainehvand; Rohana Yusof; Marc Madou. 2017. "An Effect of Magnetic Beads to Boesenbergia rotunda Antioxidant Activity Using Photoprotective Microfluidic CD." 8th European Medical and Biological Engineering Conference , no. : 139-144.
The development of accurate and rapid biosensors to detect pathogenic Salmonella enterica is an active area of interest with significant impact towards public health. An electrochemical aptasensor was developed using electrochemically-reduced graphene oxide-chitosan (rGO-CHI) composite as a conductive substrate to detect whole-cell Salmonella enterica serovar Typhimurium, a common serovar that causes foodborne infections in humans. A thiol-functionalized aptamer specific to Salmonella outer membrane protein was selected as the biorecognition element and was immobilized on rGO-CHI using glutaraldehyde as the crosslinker. The sensitivity and selectivity of this aptasensor against S. Typhimurium was investigated using cyclic voltammetry and differential pulse voltammetry techniques. The rGO-CHI composite formed a conductive coating (4.5 A m− 2) which was stable to accommodate the buildup of activating agents without degrading. The developed aptasensor is specific to Salmonella and could distinguish between Salmonella enterica cells and non-Salmonella bacteria (S. aureus, K. pneumonia and E. coli). The aptasensor exhibited a low limit of detection of 101 CFU mL− 1 for S. Typhimurium. The system was tested with artificially spiked raw chicken samples and the results were consistent with the sensitivity results obtained using with pure cultures. This shows the potential of the developed aptasensor in direct Salmonella detection in contaminated food
Ignatius Julian Dinshaw; Shalini Muniandy; Swe Jyan Teh; Fatimah Ibrahim; Bey Fen Leo; Kwai Lin Thong. Development of an aptasensor using reduced graphene oxide chitosan complex to detect Salmonella. Journal of Electroanalytical Chemistry 2017, 806, 88 -96.
AMA StyleIgnatius Julian Dinshaw, Shalini Muniandy, Swe Jyan Teh, Fatimah Ibrahim, Bey Fen Leo, Kwai Lin Thong. Development of an aptasensor using reduced graphene oxide chitosan complex to detect Salmonella. Journal of Electroanalytical Chemistry. 2017; 806 ():88-96.
Chicago/Turabian StyleIgnatius Julian Dinshaw; Shalini Muniandy; Swe Jyan Teh; Fatimah Ibrahim; Bey Fen Leo; Kwai Lin Thong. 2017. "Development of an aptasensor using reduced graphene oxide chitosan complex to detect Salmonella." Journal of Electroanalytical Chemistry 806, no. : 88-96.
This paper presents an optimized 3-coil inductive wireless power transfer system with wearable power transmitting coil (PTC), miniaturized power receiving coil (PRC), and power amplifier. The PTC is made wearable to improve system's compactness and portability. The PRC and its circuitry are sufficiently miniaturized so that they can be embedded in the tiny capsule replacing the conventional onboard battery. In addition, the power amplifier is specially designed and optimized to enable convenient fine-tune for impedance matching. This minimizes unnecessary mismatch normally contributed by changes on impedance of the power transmitting coil because of the use of different size of PTC for different patient group, deformation of the PTC, etc. The experimental test shows our proposed system obtained the power transfer efficiency at least 7.53% when 708 mW of power is transferred.
Rubel Basar; Mohd Yazed Ahmad; Jongman Cho; Fatimah Ibrahim. A 3-coil wireless power transfer system with fine tuned power amplifier for biomedical capsule. 2017 IEEE Asia Pacific Microwave Conference (APMC) 2017, 142 -145.
AMA StyleRubel Basar, Mohd Yazed Ahmad, Jongman Cho, Fatimah Ibrahim. A 3-coil wireless power transfer system with fine tuned power amplifier for biomedical capsule. 2017 IEEE Asia Pacific Microwave Conference (APMC). 2017; ():142-145.
Chicago/Turabian StyleRubel Basar; Mohd Yazed Ahmad; Jongman Cho; Fatimah Ibrahim. 2017. "A 3-coil wireless power transfer system with fine tuned power amplifier for biomedical capsule." 2017 IEEE Asia Pacific Microwave Conference (APMC) , no. : 142-145.
Dielectrophoresis (DEP) is a label-free, accurate, fast, low-cost diagnostic technique that uses the principles of polarization and the motion of bioparticles in applied electric fields. This technique has been proven to be beneficial in various fields, including environmental research, polymer research, biosensors, microfluidics, medicine and diagnostics. Biomedical science research is one of the major research areas that could potentially benefit from DEP technology for diverse applications. Nevertheless, many medical science research investigations have yet to benefit from the possibilities offered by DEP. This paper critically reviews the fundamentals, recent progress, current challenges, future directions and potential applications of research investigations in the medical sciences utilizing DEP technique. This review will also act as a guide and reference for medical researchers and scientists to explore and utilize the DEP technique in their research fields.
Nurhaslina Abd Rahman; Fatimah Ibrahim; Bashar Yafouz. Dielectrophoresis for Biomedical Sciences Applications: A Review. Sensors 2017, 17, 449 .
AMA StyleNurhaslina Abd Rahman, Fatimah Ibrahim, Bashar Yafouz. Dielectrophoresis for Biomedical Sciences Applications: A Review. Sensors. 2017; 17 (3):449.
Chicago/Turabian StyleNurhaslina Abd Rahman; Fatimah Ibrahim; Bashar Yafouz. 2017. "Dielectrophoresis for Biomedical Sciences Applications: A Review." Sensors 17, no. 3: 449.
Falls and fall-related injuries are increasingly serious issues among elderly inpatients due to population aging. The bed-exit alarm has only previously been evaluated in a handful of studies with mixed results. Therefore, we evaluated the effectiveness of a modular bed absence sensor device (M-BAS) in detecting bed exits among older inpatients in a middle income nation in East Asia. Patients aged ≥65 years on an acute geriatric ward who were able to mobilize with or without walking aids and physical assistance were recruited to the study. The total number of alarms and the numbers of true and false alarms were recorded by ward nurses. The M-BAS device is placed across the mattress of all consenting participants. Nurses’ workload was assessed using the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) score, while nurses’ perceptions were surveyed. The sensitivity of the M-BAS was 100% with a positive predictive value of 68% and a nuisance alarm rate of 31%. There was a significant reduction in total NASA-TLX workload score (mean difference = 14.34 ± 13.96 SD, p < 0.001) at the end of the intervention period. 83% of the nurses found the device useful for falls prevention, 97% found it user friendly, and 87% would use it in future. The M-BAS was able to accurately detect bed absence episodes among geriatric inpatients and alert nurses accordingly. The use of the device significantly reduced the total workload score, while the acceptability of the device was high among our nurses. A larger, cluster randomized study to measure actual falls outcome associated with the use of the device is now indicated.
Kogilavani Subermaniam; Ridgwan Welfred; Pathmawathi Subramanian; Karuthan Chinna; Fatimah Ibrahim; Mas S. Mohktar; Maw Pin Tan. The Effectiveness of a Wireless Modular Bed Absence Sensor Device for Fall Prevention among Older Inpatients. Frontiers in Public Health 2017, 4, 292 .
AMA StyleKogilavani Subermaniam, Ridgwan Welfred, Pathmawathi Subramanian, Karuthan Chinna, Fatimah Ibrahim, Mas S. Mohktar, Maw Pin Tan. The Effectiveness of a Wireless Modular Bed Absence Sensor Device for Fall Prevention among Older Inpatients. Frontiers in Public Health. 2017; 4 ():292.
Chicago/Turabian StyleKogilavani Subermaniam; Ridgwan Welfred; Pathmawathi Subramanian; Karuthan Chinna; Fatimah Ibrahim; Mas S. Mohktar; Maw Pin Tan. 2017. "The Effectiveness of a Wireless Modular Bed Absence Sensor Device for Fall Prevention among Older Inpatients." Frontiers in Public Health 4, no. : 292.